Summary: An approximate method for two parameters singularly perturbed boundary value problems having boundary layers at both end points is given. The method is motivated by the asymptotic behavior of the solution. In the outer region the solution of the problem is approximated by the zeroth order asymptotic expansion while in the inner region the solution of the problem is obtained by using B-spline collocation method. The method is iterated on the transition point of the boundary layer region. To demonstrate the applicability of the method two test examples are considered.